In the download url presented in the post there is a DataServicesCTP2Reference.chm file and if you search for BLOB, you get the following “(…) ADO.NET Data Services enables you to access binary large object (BLOB) data as a data stream. Streaming defers the loading of binary data until it is needed, and the client is able to more efficiently process this data. In order to take advantage of this functionality, the data service must implement the IDataServiceStreamProvider provider. For more information, see Data Services Providers (ADO.NET Data Services). When streaming is enabled, entity types with binary properties are returned without the binary data. Use the GetReadStream method of the DataServiceContext class to access the data stream for the binary data from the service. Similarly, use the SetSaveStream method to add or change binary data for an entity as a stream. (…)”